Putting a child into full-time day care can cost up to $15,000 in some parts of the country. That’s according to an annual study from Child Care Aware of America. The study found that it costs more to put a 4-year-old in full-time care than it does to pay public college tuition and fees in 19 different states.

For many parents, those prices don’t justify them staying at work.

Take JJ Keith, who lives with her husband and two toddlers in Los Angeles. The family couldn’t afford the nearly $20,000 a year to put both kids in daycare.

So she’s at home.

A normal day, says Keith, “is two kids who won’t nap, both want something…it’s hard to get anything done.” By “anything,” Keith means her work as a freelance writer.

Her work, which ranges from humor essays to writing for corporate publications, doesn’t bring in much money. But it’s valuable in another way. She thinks it will help her professionally once her kids are ready for school.

“So when I do re-enter full-time work, I don’t have the stink of someone who has been home with the kids for many years and is out of touch with reality,” says Keith.

Financially, that’s smart, says Tony Carnevale with the Georgetown Center on Education and the Workforce. He says “being a stay-at-home parent is a very expensive proposition. Not because of what the cost might be directly. The real cost is the earnings power you lose.”

And that can be steep. Carnevale says people with college degrees who drop out of the labor market for five years could forgo as much as $1 million over a lifetime of work, depending on the profession.

Carnevale says when that employee tries to re-enter the job market, “It’s as if you are somebody with a two-year community college degree.”

The increasing cost of daycare also ratchets up pressure on single parents. Many of them have no choice but to work, so they need to find a way to lower their childcare expenses however they can.

And that, says Helen Blank of the National Women’s Law Center, often means single mothers are left to depend on unreliable care. “When childcare falls through, and a parent can’t go to work,” she says. “We know that many parents don’t have sick leave and their job simply falls apart.”

JJ Keith, the freelance writer, has cobbled together a fairly dependable plan that lets her get some work done. For $90 a month, Keith drops her kids off at the local YMCA daycare center, while she works on her laptop in a nearly room.

But she says, without more childcare she’s just treading water. “I am not saving for retirement, I am not investing in the future,” says Keith. “We are not moving anywhere financially. We are just getting by month to month.”

Keith says she never expected a life of luxury. But she also didn't think the high price of child care would force her to choose between her kids and a full-time job.